CAR ON OPCOM SHOWING 0300(B) 0300 (A) AND 0301

2001 Vauxhall Astra • 83,000 miles

Really tired off this problem now. When easing off accelerator the car is kangarooing******** and there is a bit of engine lag when I put foot down. Got code reader and cleared codes but it keeps bringing up different codes at different times or at the same time cant really tell as the codes are not present but the codes are usually 0300 random/multiple missfire 0300 (b)missfire detected at low fuel level (tank was full before you ask, always plenty of fuel. Lol) and 0301 missfire detected in cylinder 1, please, please help. So far iv put on brand new coil pack and plugs, new fuel filter, air filter took out injectors and cleaned with carb cleaner all to no avail. The Engine Management Light never actually comes on and car always starts and runs fine apart from the kangarooing when easing off accelerator or driving slowly like over speed ramps.
im thinking now maybe faulty ECU or fuel system problem (low fuel pressure or something)
thanks

Check your fuel pressure. That is an indication of low fuel pressure or an injector problem. We dont' have any info on these cars so I can't tell you what the pressure is supposed to be. Also clean the throttle plateon bothsides with choke cleaner and the iac hole.

Thanks
iv got the info on what the pressure should be but can I test this with pc based code reader or do I need to buy a fuel pressure tester and connect it to the fuel pressure valve, Iv just recently bought a sealey compression tester can I use that in anyway?